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Wednesday, February 10, 2010

What If It Happened Here?

The 7.0 magnitude quake that has flattened the Haitian capital, Port-au-Prince, should give East Africans a pause for thought. What if a similar quake hit here? How prepared are we? As it turns out, not very. And such an event is not as rare around these parts as some would like to think.

According to Professor Chris Hartnady, a former Associate Professor in the Department of Geological Sciences at the University of Cape Town, “Large areas of the African Continent are in an unstable, tectonically active, state and, especially in the mountain regions, substantial danger is posed to growing populations.” Between 1980 and April 2002, the continent was hit by over 50 serious earthquakes, resulting in over 23,000 deaths and injuries.

In the East African region, a number of destructive earthquakes, some causing loss to life, were reported during the last century. For example, the port city of Massawa in Eritrea was destroyed by an earthquake in 1921. Ethiopia has been rocked many times by major earthquakes such as the 1960 Awasa earthquake, the 1961 Kara Kore earthquake which completely destroyed the town of Majete and severely damaged Kara Kore town, the 1969 Serdo earthquake in which four people were killed and 24 injured, 1989 Dobi graben earthquake which destroyed several bridges on the highway connecting the port of Assab to Addis Ababa, the 1983 Wondo Genet and the 1985 Langano earthquakes which caused damage in parts of the main Ethiopian rift. In Uganda, damaging earthquakes include the 1945 Masaka quake in which five people were killed, the Toro quake of 1966 which killed 160 people were killed and damaged 7000 buildings, and the 1994 Kismoro earthquake which killed eight people. In Malawi, the 1989 Salima earthquake killed nine people.

East Africa's Great Rift Valley runs along a geological fault line which, though being stretched by forces that could one day lead to East Africa splitting from the main continent, has largely escaped major quakes in recent years. But this hasn’t always been so. Earthquakes of magnitude 7+ (equal to or greater than the Haitian earthquake) have been recorded in Tanzania in 1910, Kenya in 1928 and more recently in the Sudan in 1990. While in the past, the human toll has been blunted largely due the sparsity of dwellings, rapid urbanisation is increasing risks and costs of disaster. The East African Rift System (EARS) contains some of the most densely populated areas on the continent (e.g., Virunga Mountains region between Uganda, Rwanda and DR Congo). According to the report of an “Expert Workshop on Earthquakes and Related Geo-Hazards in Africa” held in Nairobi, Kenya, in 2004, a future recurrence of a major earthquake of the size of the 1910 event in Rukwa (at 7.4, Africa’s largest earthquake in the 20th Century) would have devastating consequences not only in these areas, but also in several cities (with dominantly Westernized types of construction) on the East Africa coast line, such as Mombasa (Kenya), Dar es Salaam (Tanzania) and Beira (Mozambique).

Alarmingly, this nightmare scenario has not shaken policymakers in the region out of their slumber. In 2007, after a series of earth tremors that caused panic in Nairobi, Major Stephen Sane, acting head of Kenya's National Disaster Operations Centre, admitted that Kenya lacked the basic rescue equipment and the emergency medical staff required in the event of a serious earthquake. "Our disaster preparedness appears to be whimsical. It has not been taken seriously at the policy level," he said. The then Architectural Association of Kenya chairman, Gideon Mulyungi, estimated that 90 percent of buildings outside Nairobi's city centre were not professionally built warning “we could have a major disaster on our hands in the event of a powerful earthquake.”

And, it seems, we are not learning the lessons of previous disasters. Following the American embassy bombing in Nairobi in 1998 which caused an adjacent four-storey building to collapse burying hundreds of people, the Kenyan government had to ask for help from foreign rescue teams. Though a Kenyan rescue unit was later sent for training in Israel, the government did not acquire the necessary equipment to look for bodies and survivors buried under rubble. As a result, when a building under construction collapsed in Nairobi 8 years later, again burying dozens alive, Kenya still sought Israeli help. As Margareta Wahlström, UN Assistant Secretary-General for Disaster Risk Reduction (DRR), has said "we often look at disasters as events that happen, then we go back to normal life." She added: “This is no longer possible due to the high cost of disasters.”

In the case of earthquakes, disaster-preparedness need not cost the earth. One important prerequisite is to tap into and expand the local knowledge base. According to the report from the 2004 meeting in Nairobi, while particular seismic events cannot be predicted, the general level of seismicity across broad areas can be forecast for up to hundreds of years in the future. Nearly all countries in the region now have regional seismic hazard maps, which can be used to identify the best (or the worst) place to locate buildings. It would thus be relatively easy to quickly find the most vulnerable geographic zones and populations, and commission further research to augment our understanding. This enhanced knowledge would help our scientists undertake rigorous, scientific, evaluation of large developments (such as big dam projects) likely to trigger damaging seismic events, and advise policymakers accordingly.

The experts proposed another low-tech and cost-effective means of reducing our vulnerability to quakes. During the 1910 quake in Rukwa, Tanzania, only German colonial buildings were destroyed or damaged. African construction methods proved superior. This implies that urban centres with dominantly Westernized types of construction are more vulnerable and would benefit from a traditional retooling. It is therefore important to study how traditional construction methods adapted historically to the natural environment.

A final measure identified is the creation of an informed public which can apply the geologic knowledge held by specialists. “In Africa, the need is not for sophisticated high-technology approaches, such as prediction research or early warning systems, but for better community preparedness to live with earthquakes so that the need to ‘predict’ is reduced.” In other words, earthquakes need not become major disasters and prevention is always better (and cheaper) than cure.